Rockwell Automation 1398-PDM-xxx IQ Master Version 3.2.4 for IA-2000 and IQ-5000 Positioning Drive Modules, IQ-55 - Manual (Page 415)

Application Examples • Vertical, Form, Fill and Seal 393
Publication 1398-PM601A-EN-P — October 2000
APPENDIXES
lish a window around the nominal registration mark position where it will recognize registration sensor
transitions. Any sensor transitions outside this window are ignored. The controller must detect the regis-
tration marks and adjust the motion so that the cut and seal is in the proper position relative to the print-
ing on the film.
The ULTRA Plus or IQ Solution
The ULTRA Plus or IQ controller with the optional operator terminal provides great flexibility as a pro-
grammable motion controller for interfacing to the machine. The optically isolated I/O can interface to a
wide variety of sensors and output devices. The program shown in this application note provides a seal
output which turns on to indicate that the material is in position and the seal operation can begin. A
ready input indicates that the operation is complete and the controller can begin the next move.
The operator interface allows the operator to change variables for setup while the machine is running.
The programmable function keys on the operator terminal can also replace pushbuttons and switches for
stopping, starting, and pausing the machine. The program listed in this application note uses inputs for
these functions, and the function keys can easily be set up to either replace or supplement the I/O.
The accuracy of registration is affected by the speed of the sensor used, resulting in an error that is a
function of the material speed when the registration mark is sensed. The registration sensor output is
connected to input 11 on the ULTRA Plus or IQ controller. Input 11 is the trigger for a hardware latch
which latches the position within 1.5 microseconds of the off to on transition of the sensor. The sensor
used should have a sinking output (NPN), which turns on when the registration mark is detected. The
ULTRA Plus or IQ controller records the position where the registration mark is detected, and at the end
of the move compares the distance moved past the registration mark to the desired registration distance.
If the two distances are different, the correction is added to the next move. This technique works well
for corrections needed due to material stretch or for printing variations which change gradually as the
material is unrolled, but it does not work well if the variation from one mark to the next is significant.